This invention relates to systems and methods for affixing a fitting to the exterior surface of a pipeline in a manner that can be accomplished while fluid is flowing under pressure within the pipeline. The invention is particularly useful for applying a fitting to a pipeline to permit the pipeline to be tapped so that the pipeline can be plugged or for the purpose of providing a branch fitting. “Pipe” as used herein is inclusive of any tubular member made of metal for carrying fluid (liquid or gas) and specifically is inclusive of “pipeline.” Machines for tapping an opening in a pipe are well-known. Prior issued United States patents for tapping machines include U.S. Pat. No. 3,614,252 entitled TAPPING APPARATUS; U.S. Pat. No. 4,579,484 entitled UNDERWATER TAPPING MACHINE; U.S. Pat. No. 4,880,028 entitled COMPLETION MACHINES; U.S. Pat. No. 5,439,331 entitled HIGH PRESSURE TAPPING APPARATUS; U.S. Pat. No. 5,612,455 entitled METHOD OF INSERTING A SENSOR INTO A PIPELINE; and U.S. Pat. No. 6,012,878 entitled PRESSURE BALANCE SUBSEA TAPPING MACHINE. Tapping machines of the kind described in the above-mentioned U.S. patents are for tapping a hole in a pipe or a pipeline while liquids or gases are flowing through it—that is, while the pipe is under pressure. Tapping procedures of this type are customarily carried out for one of two purposes—that is, to provide a branch fitting or to enable fluid flow through the pipe to be blocked. Other examples of prior art that describe and illustrate plugging the interior of a pipe usually associated with first tapping the pipe, include the following United States patents:
PATENT NO.INVENTORTITLE3,599,663FreemanHot Tapping Apparatus3,626,475HicksHigh Temperature Pipe-Plugging Apparatus3,665,966Ver NooyPipe Plugger3,872,880Ver Nooy et al.Plugging Apparatus4,411,459Ver NooyBranch Fitting forProviding Access to theInterior of a Pipe5,443,095Glossop, Jr.Fluid Blocking Device5,531,250Freeman et al.Device for Plugging theInterior of a Pipe
Tapping a pipe normally involves the use of a circular saw, examples of which are illustrated and described in the following United States patents:
PATENT NO.INVENTORTITLE5,360,300SullivanCutter Shell5,451,128HattersleyCutter Tool HavingRemovable Teeth5,466,099Sullivan et al.Cutter Shell forForming Holes of ImprovedCylindricality
Devices for plugging a pipe that has been tapped are also well known as illustrated by U.S. Pat. No. 5,531,250 entitled DEVICE FOR PLUGGING THE INTERIOR OF A PIPE.
Patents that teach fittings attachable to the exterior of a pipeline include the following:
PATENT NO.DATE ISSUEDINVENTOR2,775,469Dec. 25, 1956Brown, et al.3,433,507Mar. 18, 1969Ver Nooy4,768,813Sep. 6, 1988Timmons5,040,828Aug. 20, 1991Kane5,374,087Dec. 20, 1994Powers5,553,898Sep. 10, 1996Rogers, Jr.5,806,896Sep. 15, 1998Sato, et al.5,967,168Oct. 19, 1999Kitani, et al.6,019,398Feb. 1, 2000Powers6,131,957Oct. 17, 2000Kikuo Saito, et al.6,648,377Nov. 18, 2003Marandi
These patents are incorporated herein by reference since they provide a thorough background relating to the subject matter of the present invention.